Why do Rangers get limited spells known and Paladins get to prepare proportionally more spells?

Why do Rangers get limited spells known and Paladins get to prepare proportionally more spells per day? Would it be game breaking to give Rangers prepared spells in the same manner? (Ty for reading!) I ask because in my experience most Paladins are using spell slots for divine smites, less for actual spellcasting, so I'm confused as to why they get more daily diversification than Rangers